German forces had been routed during the Allied break-out from Normandy. The Allies advanced rapidly against an enemy that put up little resistance. But after the liberation of Paris in late August 1944, the Allies paused to re-group and organise before continuing their advance from Paris to the Rhine. The pause allowed the Germans to solidify their lines — something they had been unable to do west of Paris.

While Generals Montgomery and Bradley each favored relatively direct thrusts into Germany (with Montgomery and Bradley each offering to be the spearhead of such an assault), Eisenhower disagreed. Instead, he chose a "broad-front" strategy, which allowed the Allies to gain ground from the beaten Germans in all sectors, allowed the advancing Allied forces to support each other, and minimized the difficulty of supplying the most advanced forces.

The rapid advance through France had caused considerable logistical strain, made worse by the lack of any major port other than the relatively distant Cherbourg in western France. Although Antwerp was seen as the key to solving the Allied logistics problems, its port was not open to Allied shipping until the Scheldt estuary was clear of German forces. As the campaign progressed, all the belligerents, Allied as well as German, felt the effects of the lack of suitable replacements for front-line troops.

There were two major defensive obstacles to the Allies. The first was the natural barriers made by the rivers of eastern France. The second was the Siegfried Line, which fell under the command, along with all Wehrmacht forces in the west, of Field MarshalGerd von Rundstedt.

Although the breakout from Normandy had taken longer than planned, the advances until September had far exceeded expectations. Bradley, for example, by September had four more divisions than planned and all of his forces were 150 mi (240 km) ahead of their expected position. One effect was that insufficient supplies could be delivered to the various fronts to maintain the advance: demand had exceeded the expected needs.

Mulberry 'A' off Omaha Beach was critical in the early days for Allied supplies.

Much war material still had to be brought ashore across the invasion beaches and through the one remaining Mulberry harbour (The other had been destroyed in an English Channel storm). Although small harbours, such as Isigny, Port-en-Bessin, and Courcelles, were being used, the major forward ports such as Calais, Boulogne, Dunkirk and Le Havre either remained in German hands as "fortresses" or had been systematically destroyed. The availability of Cherbourg had been valuable until the breakout, but then the shortage of transport to carry supplies to the rapidly advancing armies became the limiting factor.

Although fuel was successfully pumped from Britain to Normandy via the Pluto pipeline, this still had to reach the fronts, which were advancing faster than the pipelines could be extended.[4] The railways had been largely destroyed by Allied attacks and would take much effort to repair, so fleets of trucks were needed in the interim.[5] In an attempt to address this acute shortage of transport, three newly arrived US infantry divisions—the 26th, 95th, and 104th—were stripped of their trucks in order to haul supplies.[6] Advancing divisions of the US 12th Army Group left all their heavy artillery and half their medium artillery west of the Seine, freeing their trucks to move supplies for other units.[7] Four British truck companies were loaned to the Americans.[8] Unfortunately, 1,500 other British trucks were found to have critical engine faults and were unusable, limiting assistance from that quarter.[9] The Red Ball Express was an attempt to expedite deliveries by truck but capacity was inadequate for the circumstances.[10]

The Sixth Army Group advancing from southern France were supplied adequately from Toulon and Marseille because it had captured ports intact and the local railway system was less damaged. This source supplied about 25% of the Allied needs.

The US supply organization—Communications Zone (COMZ)—is perceived to have failed to expedite solutions and to have been far too bureaucratic, employing 11,000 staff. COMZ and its commander, General John C. H. Lee, were roundly criticised by other American generals. Failure to supply forward units led to unofficial arrangements, with pressed units "diverting" supplies intended for others. Eisenhower felt he could not exert authority since COMZ was directly answerable to Washington and not to SHAEF, but Eisenhower has been criticised for not exerting more pressure and influence than he did.

At this time the main Allied supply lines still ran back to Normandy, presenting serious logistical problems. The solution was to get Antwerp into operation quickly. Although this major port had been captured almost intact, the mere occupation of Antwerp was not enough, because the 21st Army Group failed to gain sea access by clearing the Scheldt estuary.

German armies had lost large numbers of troops in Normandy and the subsequent pursuit. To counteract this, about 20,000 Luftwaffe personnel were reallocated to the Army, invalided troops were redrafted into the front line and Volkssturm units were formed using barely trained civilians.

British manpower resources were limited after five years of war and through worldwide commitments. Replacements were no longer adequate to cover losses and some formations were disbanded to maintain the strength of others. The Canadians were also short of manpower, due to a reluctance to require conscripts to serve outside Canada or Canadian waters. This had arisen from internal Canadian political difficulties during World War I and there had been a wide consensus against conscription for overseas service.[11][note 1]

American losses now called on replacements from the US. They were often inexperienced and unused to the harsh conditions of the latter part of the campaign. There were also complaints about the poor quality of troops released into the infantry from less-stressed parts of the US Army. At one point, after the Battle of the Bulge had highlighted the shortage of infantrymen, the US Army relaxed its embargo on the use of black soldiers in combat formations.[12] Black volunteers performed well and prompted a permanent change in military policy.

By the beginning of the next year, the war's outcome was clear. It became increasingly difficult to persuade Allied troops to risk their lives when peace was in sight. No one wished to be the last man killed.

British infantry of the 1st Battalion, Hampshire Regiment crossing the Seine at Vernon, 28 August 1944

The Channel ports were urgently needed to maintain the Allied armies. By the time that Brussels was liberated, it had become difficult to supply the British 21st Army Group adequately. Indeed, one corps—VIII Corps—was withdrawn from active service to free its transport for general use. The Canadian First Army was tasked with liberating the ports during its advance along the French coast.[13] The ports involved were Le Havre, Dieppe, Boulogne, Calais, and Dunkirk in France, as well as Ostend in Belgium. Adolf Hitler had appreciated their strategic value. He issued a Führer Order declaring them to be "fortresses" that must receive adequate materiel for a siege and be held to the last man.

Dieppe was evacuated by the Germans before Hitler's order had been received and, consequently, the Canadians took it with little trouble and with the port installations largely intact. Ostend had been omitted from the Führer Order and was also undefended, although demolitions delayed its use. The other ports were defended to varying degrees, however, and they required substantial work to bring them into use, except for Dunkirk which was sealed off to the rear of the Allied advance.

The first operation of the Rhineland Campaign, Market Garden, was commanded by Montgomery and was to secure a bridgehead over the Rhine in the north, at Arnhem, which would outflank the Siegfried Line.

Market Garden had two distinct parts. Market was to be the largest airborne operation in history, dropping three and a half divisions of US, British, and Polish paratroopers to capture key bridges and prevent their demolition by the Germans. Garden was a ground attack by the British 2nd Army across the bridges. It was assumed that the German forces would still be recovering from the previous campaign and opposition would not be very stiff for either operation.

If successful, the Allies would have a direct route into Germany that bypassed the main German defenses and also seize territory from which the Germans launched V-1s and V-2s against London, Antwerp and elsewhere.

Eisenhower approved Market Garden. He gave supply priority to the 21st Army Group and diverted the US 1st Army to the north of the Ardennes to stage limited attacks to draw German defenders south, away from the target sites.

At first, it went well. The US 101st and 82nd Airborne Divisions took their objectives at Eindhoven, Veghel and Nijmegen. Although their landings outside Arnhem were on target, the British 1st Airborne Division landing zones were some distance from Arnhem bridge and only on the north side of the river. Problems arose when the British 1st Airborne lost vital equipment—jeeps and heavy anti-tank guns—when gliders crashed. There had also been a severe underestimation of German strength in the area. To make matters worse, poor weather prevented aerial reinforcements and drastically reduced resupply. German resistance to the forces driving to Arnhem was highly effective, and a copy of the Allied battle plan had been captured.

In the end, Market Garden was unsuccessful. Arnhem bridge was not held and the British paratroops suffered tremendous casualties - approximately 77%.

On 21 September 1944, the advance began. The Canadian 4th Armoured Division, moving north toward the south shore of the Scheldt around the Dutch town of Breskens were the first Allied troops to face the formidable obstacle of the double line of the Leopold and Dérivation de la Lys Canals. The canals were crossed and a bridgehead established, but fierce counter-attacks by the Germans forced them to withdraw with heavy casualties. The 1st Polish Armoured Division had greater success, moving northeast to the coast, occupying Terneuzen and clearing the south bank of the Scheldt eastward to Antwerp. It was by then clear, however, that any further advances would be at tremendous cost.

British assault troops advancing near Flushing with shells bursting ahead during the Scheldt operation

Field-Marshal Montgomery issued a directive that made the opening of the Scheldt estuary the top priority. To the east, the British 2nd Army attacked westward to clear the Netherlands south of the Maas River. This helped secure the Scheldt region from counter-attack.

Operation Vitality—the third major phase of the Battle of the Scheldt—began on 24 October. The Canadian 2nd Infantry Division began its advance toward South Beveland, but was slowed by mines, mud and strong enemy defences. The British 52nd (Lowland) Division made an amphibious attack to get in behind the Germans' Beveland Canal defensive positions. Thus, this formidable defence was outflanked, and the Canadian 6th Infantry Brigade began a frontal attack in assault boats. The engineers were able to bridge the canal on the main road. With the canal line gone, the German defence crumbled and South Beveland was cleared. The third phase of the Battle of the Scheldt was now complete.

The final phase, Operation Infatuate was the attack on the heavily fortified island of Walcheren at the mouth of the West Scheldt. The island's dykes were breached by attacks from RAF Bomber Command on 3, 7, and 11 October. This flooded the central part of the island, forcing the German defenders onto the high ground and allowing the use of amphibious vehicles. Units of the Canadian 2nd Infantry Division attacked the causeway on 31 October, and after a grim struggle, established a precarious foothold. They were relieved by a battalion of the British 52nd (Lowland) Division. In conjunction with the waterborne attacks, the 52nd continued the advance.

The amphibious landings began on 1 November with units of the British 155th Infantry Brigade landing on a beach in the south-eastern area of Vlissingen. During the next few days, they engaged in heavy street fighting against the German defenders. Also on 1 November, after a heavy naval bombardment by the British Royal Navy, troops of 4th Commando Brigade, (with units of 10th Inter Allied Commando, consisting mainly of Belgian and Norwegian troops), supported by specialised armoured vehicles of the 79th Armoured Division were landed on both sides of the gap in the sea dyke. Heavy fighting ensued. A smaller force moved south-eastward, toward Vlissingen, while the main force went northeast to clear the northern half of Walcheren to link up with the Canadians who had established a bridgehead on the eastern part of the island. Fierce resistance was again offered by German troops defending the area, and fighting continued until 7 November. However, the action ended on 8 November after a force of amphibious vehicles entered Middelburg, the capital of Walcheren.

Meanwhile, the Canadian 4th Armoured Division had pushed eastwards past Bergen-op-Zoom to Sint Philipsland where it sank several German vessels in Zijpe harbour. With the approaches to Antwerp free, the fourth phase of the Battle of the Scheldt was complete; on 28 November, the first convoy entered the port.

Montgomery's 21st Army Group were tasked with clearing the west bank of the Rhine downstream from the Krefeld area. The approach was for the Canadian 1st Army—strengthened by XXX Corps—to advance south-eastward between the Rhine and Maas rivers while the US 9th Army advanced north eastwards from the Roer. The two armies would meet in the Geldern area. The British 2nd Army stayed west of the Maas, apart from two divisions that reinforced the Anglo-Canadian advance, but the German High Command were initially convinced that they were the principal threat and deployed their reserves in anticipation of an assault from Venlo.

The two operations were delayed by the 'Battle of the Bulge' but they were rescheduled for 8 February 1945. Although the Anglo-Canadian attack (Operation Veritable) started on time, the US assault (Operation Grenade) was delayed by the threat and then the danger of flooding by water released from the Roer dams. This delay allowed the Germans to concentrate their defence on the Anglo-Canadian assaults, but they were unable to do much more than to slow it down in localised areas. When the Americans were able to advance, some two weeks later, there were few reserves left to face them and they made rapid progress until they encountered the German rearguard near the Rhine.

The two prongs met at Geldern, then pushed towards Rees, finally expelling German forces on 21 March.

The US 1st Army was focused on capturing the city of Aachen, which had to be dealt with before advancing to assault the Siegfried Line itself. Initially, the city of Aachen was to be bypassed and cut off in an attempt by the Allies to imitate the Blitzkrieg tactics the Germans had so effectively used (see below). However, the city was the first to be assaulted on German soil and so had huge historical and cultural significance for the German people. Hitler personally ordered that the garrison there be reinforced and the city held. This forced the Allied commanders to re-think their strategy.

Some historians, including Stephen Ambrose, have suggested that the siege of Aachen was a mistake. The battle stalled the eastward advance by the Allies and caused approximately 5,000 Allied casualties. The fighting was, by all accounts, brutal street-to-street, house-to-house style urban combat and tied up the available rescources of the advancing Allied armies. Ambrose has suggested that a more effective strategy would have been to have isolated the garrison at Aachen and continue the move east into the heart of Germany. In theory, this would have eliminated the ability of the German garrison to operate as a fighting force by cutting off their supply lines. This might have forced them to surrender or to move out of the city in an attempt to re-establish their supply lines. In the case of the latter, a confrontation in a more neutral setting would probably have resulted in fewer military and civilian casualties.

In late August, the US 3rd Army started to run low on fuel. This situation was caused by the rapid Allied advance through France, and compounded by the shift of logistical priority to the northern forces to secure Antwerp. By 1 September 1944, with the last of its fuel, the 3rd Army managed one final push to capture key bridges over the Meuse River at Verdun and Commercy. Five days after that, however, the critical supply situation effectively caused the 3rd Army to grind to a halt, allowing previously routed German forces to regroup and the reinforcement of their strongholds in the area.

Soon after, the 3rd Army came up against Metz, part of the Maginot Line and one of the most heavily fortified cities in Western Europe. The city could not be bypassed, as several of its forts had guns directed at Moselle crossing sites and the main roads in the area. It could be also be used as a stronghold to organize a German counter-attack to the 3rd Army's rear. In the following Battle of Metz, the 3rd Army, while victorious, took heavy casualties.

Following Metz, the 3rd Army continued eastwards to the Saar River and soon began their assault on the Siegfried Line.

Hürtgen Forest was seen as a possible location for incursions into the American flank and the river dams in the area were a threat to the Allied advance downstream, so an assault to clear the area was started on 19 September 1944. German defence was more stubborn than expected and the terrain was highly favourable to defence, largely negating the American advantages of numbers and quality of troops. The battle — expected to last a few weeks — continued until February 1945 and cost 33,000 casualties (from all causes).

The value of the battle has been disputed. Modern historians argue that the outcome was not worth the foreseeable losses and, in any case, the American tactics played into German hands.[14]

Operation Queen was a combined Allied air-ground offensive against the German forces at the Siegfried Line, which was conducted mainly by the combined effort of the US 9th and 1st Armies. The principal goal of the operation was to advance to the Rur River and to establish several bridgeheads over it, for a subsequent thrust into Germany to the Rhine River. Parts of this operation also included further fighting in the Hurtgen Forest. The offensive commenced on 16 November with one of the heaviest tactical air bombardments by the western Allies of the war. Although the German forces were heavily outnumbered, the Allied advance was very slow. After four weeks of intensive fighting, the Allies reached the Rur, but were not able to establish any bridgeheads over it. Fighting in the Hurtgen Forest also bogged down. The exhaustive fighting during Queen caused the Allied troops to suffer heavy casualties and eventually the Germans launched their own counteroffensive—Operation Wacht am Rhein—on 16 December, which would lead to the Battle of the Bulge.

American soldiers taking up defensive positions in the Ardennes during the Battle of the Bulge

The Germans had been preparing a massive counter-attack in the West since the Allied breakout from Normandy. The plan called Wacht am Rhein ("Watch on the Rhine") was to attack through the Ardennes and swing North to Antwerp, splitting the American and British armies. The attack started on 16 December in what became known as the Battle of the Bulge. Defending the Ardennes were troops of the US 1st Army. After initial successes in bad weather, which gave the Germans cover from the Allied air forces, the Allies launched a counterattack to clear them from the Ardennes. The Germans were eventually pushed back to their starting points by 25 January 1945.

The Germans launched a second, smaller offensive (Nordwind) into Alsace on 1 January 1945. Aiming to recapture Strasbourg, they attacked the 6th Army Group at multiple points. Because Allied lines had become severely stretched in response to the crisis in the Ardennes, holding and throwing back the Nordwind offensive was a costly affair that lasted almost four weeks. Allied counter-attacks restored the front line to the area of the German border and collapsed the Colmar Pocket.

The pincer movement of the Canadian 1st Army, advancing from the Nijmegen area in Operation Veritable, and the US Ninth Army, crossing the Rür in Operation Grenade was planned to start on 8 February 1945, but it was delayed by two weeks when the Germans flooded the Roer valley by destroying the floodgates of two dams on the upper Roer (Rur Dam and Urft Dam). During the two weeks that the little river was flooded, Hitler did not allow Rundstedt to withdraw German forces behind the Rhine, arguing that it would only delay the inevitable fight. Hitler ordered him to fight where his forces stood.

By the time the water had subsided and the US Ninth Army was able to cross the Roer on 23 February, other Allied forces were also close to the Rhine's west bank. German divisions which had remained on the west bank of the Rhine were cut to pieces and 280,000 men were taken prisoner. The stubborn German resistance had been costly to them; their total losses reached an estimated 400,000 men.[15]

US soldiers cross the Rhine river in assault boats

The Allies crossed the Rhine at four points. One crossing was an opportunity taken by US forces when the Germans failed to blow up the Ludendorff Bridge at Remagen, one crossing was a hasty assault, and two crossings were planned.

Bradley told General Patton—whose US Third Army had been fighting through the Palatinate—to "take the Rhine on the run". The Third Army did just that on the night of 22/23 March, crossing the river with a hasty assault south of Mainz at Oppenheim.

In the north, the Rhine is twice as wide, with a far higher volume of water, than where Americans crossed. 21st Army Group commander Montgomery decided it could only be crossed safely with a carefully prepared attack. This was Operation Plunder, the crossing of the Rhine at Rees and Wesel on the night of 23/24 March. It included the largest single drop airborne operation in history, Operation Varsity.

^The legal embargo on compulsory overseas service was the subject of a national plebiscite on 27 April 1942. Around 64% of the population supported the removal of the restriction, but in FrancophoneQuebec, 72% were against.